Year	Years
1990	70.4
1991	69.8
1992	68.8
1993	67.9
1994	67.4
1995	67.7
1996	68.7
1997	69.4
1998	69.8
1999	69.9
2000	70.1
2001	70.3
2002	70.8
2003	71.4
2004	71.9
2005	72.4
2006	72.8
2007	73.2
2008	74
2009	75
2010	75.8
2011	76.3
2012	76.5
2013	76.6